Portable electronic device and method for coupling power thereto

ABSTRACT

A novel portable electronic device comprising a first housing portion (106) having a first battery (135) integrally associated with said first housing portion and a second housing portion (104) having a second battery (102) operatively coupled to an external surface of the second housing portion. Also, a method for coupling power to a portable electronic device comprises steps of providing a recessed region in a first housing portion for receiving a first battery and operatively coupling a second battery to an external surface of a second housing portion.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to portable electronic devicesand more specifically to a device and method for coupling power to aportable electronic device.

2. Description of the Related Art

Consumer demands have fueled technological advances in the area ofportable electronics. Through aggressive development and manufacturing,the industry has accomplished increased miniaturization of electroniccomponents resulting in the advent of extremely lightweight anddimensionally constrained portable electronic devices, such as laptopcomputers and cellular radiotelephones. The current market has becomeinundated with a variety of the portable electronic devices from whichthe consumer can choose to purchase. Oftentimes the main selling pointsof the portable electronic device include operational features andcosmetic appearance.

One such operational feature of the portable electronic device is itsduration of continuous operation, i.e., its amount of "talk" time and"standby" time. Portable electronic devices are typically powered by arechargeable battery pack--multiple rechargeable electrochemical cellsdisposed within a housing--that is manufactured to attach to theportable electronic device. Because of the relatively large weight andsize of rechargeable battery packs, current portable electronic devicestypically only provide for attachment of a single, main rechargeablebattery pack. Therefore, such portable electronic devices are limited tocontinuous operation only during the period between recharges of themain rechargeable battery pack. Such limitations are undesirable to auser that requires a longer duration of continuous operation and doesnot wish to sacrifice portability by having to carry additionalrechargeable battery packs. Therefore, it would be beneficial to have aportable electronic device with increased of continuous operationwithout hampering its portability.

To increase the duration of continuous operation, it is known to attachan auxiliary rechargeable battery pack to the portable electronic deviceto supplement the main rechargeable battery pack in powering theportable electronic device. Current latching mechanisms for attachingrechargeable battery packs include parallel channels formed in therechargeable battery pack that interlock with corresponding parallelrails disposed on the portable electronic device; and protruding membersextending from the rechargeable battery pack that mate with indentationsdisposed about a cavity formed in the housing of the portable electronicdevice when the rechargeable battery pack is inserted into the cavity.However, because the auxiliary rechargeable battery pack is optional andneed not always be attached to the portable electronic device for theportable electronic device to operate, current latching mechanisms areunacceptable for attaching an auxiliary rechargeable battery pack due totheir adverse cosmetic impact. Without attachment of the auxiliarybattery pack, for example, both the parallel rails on the portableelectronic device and the housing cavity on the portable electronicdevice would remain unoccupied and exposed.

Therefore, what is needed is an effective latching mechanism forattaching an optional accessory, such as a rechargeable battery pack, toa portable electronic device, such that the appearance of the portableelectronic device is minimally affected when the optional accessory isnot attached.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a front and right side perspective view of a portableelectronic device having an optional battery pack attached thereto.

FIG. 2 illustrates a rear, left side, and top perspective view of theportable electronic device.

FIG. 3 illustrates a bottom plan view of the portable electronic device.

FIG. 4 illustrates a front, right side, and top perspective view of theoptional battery pack employing a latching mechanism.

FIG. 5 illustrates a front, right side, and top perspective view of alatch of the latching mechanism.

FIG. 6 illustrates a front elevational view of the optional battery packhaving a front surface removed and multiple positions of the latch.

FIG. 7 llustrates a cross-sectional view of the portable electronicdevice and attached optional battery pack taken along section lines 1--1of FIG. 1.

FIG. 8 illustrates a flow chart of a method of latching the optionalbattery pack to the portable electronic device.

FIG. 9 illustrates the portable electronic device having an optionalbattery pack attached thereto and an associated accessory.

FIG. 10 illustrates the portable electronic device in a closed positionwith a main battery pack detached showing the inside and rear wall of arecessed region for receiving the main battery pack;

FIG. 11 illustrates the portable electronic device in a closed positionwith a main battery pack detached showing the inside and front wall ofthe recessed region;

FIG. 12 illustrates a front elevational view of the main batterydetached from the portable electronic device;

FIG. 13 illustrates a rear elevational view of the main battery detachedfrom the portable electronic device; and

FIG. 14 illustrates a side elevational view of the main battery detachedfrom the portable electronic device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A latching mechanism disposed on an optional accessory for attaching theoptional accessory to a portable electronic device includes a supportand a moveable latch that mate with a retaining device disposed on theportable electronic device. The support and moveable latch are disposedon opposite ends of the optional accessory. The retaining deviceincludes receptacles and a notch disposed on opposite ends as well asdifferent sides of the portable electronic device. The retaining deviceis sized and oriented to minimally impact the appearance of the portableelectronic device when the optional accessory is not attached thereto.Attachment of the optional accessory to the portable electronic deviceis accomplished by engaging the moveable latch with the notch as well ascontacting the support and the receptacles. The moveable latch exerts aforce on the notch drawing the support into snug contact with thereceptacles. The force is exerted in a plane parallel to a side of theoptional accessory that extends between the ends thereof.

FIG. 1 illustrates a front and right side perspective view of a portableelectronic device having an optional battery pack attached thereto. Aportable radiotelephone 100 and an optional battery pack 102 are shownattached in FIG. 1. The portable radiotelephone 100 includes a portableradiotelephone housing 104. The portable radiotelephone housing 104 ispreferably molded from a suitable polymer material, such aspolycarbonate. The portable radiotelephone housing 104 includes a lowerhousing portion 106 and an upper housing portion 108. The lower andupper housing portions 106, 108 are rotatably coupled via a hinge 110disposed to extend planarly from a lower top end surface 112 of thelower housing portion 106. An antenna 114 extends perpendicularly fromthe lower top end surface 112. The antenna 114, which is coupled to atransceiver circuit 700 (see FIG. 7) disposed within the portableradiotelephone housing 104, permits the portable radiotelephone 100 tooperate in a cellular radiotelephone environment by communicating with afixed site cellular base station 116 via radio frequency waves 118.

The lower housing portion 106 includes a lower rear surface 120 and alower front surface 121 extending downward from the lower top endsurface 112 between a lower bottom end surface 122, a lower left surface124, and a lower right surface 126. The lower rear surface 120 includesan optional battery pack retaining device 123 which will be furtherdiscussed in relation to FIGS. 2 and 3 below. The lower front surface121 includes a display 128 disposed above a keypad 130. The display 128,which may be a liquid crystal display (LCD) or a light emitting diode(LED) type display, provides visual information to a user including, forexample, the current amount of charge remaining in the optional batterypack 102. The keypad 130 allows the user to power the portableradiotelephone 100 on and off and initiate calls by inputting andsending numbers.

The upper housing portion 108 includes an upper rear surface 132 and anupper front surface 133 extending upward from the hinge 110 and betweenan upper bottom end surface 134, a sloped upper top end surface 136, anupper left surface 138, and an upper right surface 140. The upper rearsurface 132 includes a main battery pack 135 which is removably attachedthereto for providing power to the transceiver circuit 700 (see FIG. 7)of the portable radiotelephone 100. The main battery pack 135 and theportable radiotelephone housing 104 are manufactured so that the mainbattery pack 135 is flush with the upper rear surface 132 when attached.The upper front surface 133 includes a concave speaker bezel 142 havingopenings (see FIG. 3). Positioned behind the openings in the concavespeaker bezel 142 and out of view is a speaker for providing audiocommunication to a user and from which a user may be audibly alertedthat the main battery pack 135 or the optional battery pack 102providing power to the portable radiotelephone 100 is nearing depletion.

The optional battery pack 102 includes an optional battery pack housing144. The optional battery pack housing 144 is preferably molded from asuitable polymer material, such as polycarbonate. The optional batterypack housing 144 includes a front surface 146 and a rear surface 148extending between a top end surface 150, a bottom end surface 152, aright side surface 154, and a left side surface 156. The optionalbattery pack 102 includes a latching mechanism 160 for attaching theoptional battery pack 102 to the portable radiotelephone 100 so that thelower rear surface 120 of the portable radiotelephone housing 104 andthe front surface 146 of the optional battery pack housing 144 aremaintained in juxtaposition. The latching mechanism 160 includes a latch162 extending outward from the top end surface 150 of the optionalbattery pack housing 144 and engaging the optional battery packretaining device 123 of the portable radiotelephone housing 104. Thelatching mechanism 160 further includes a support 164 extending planarlyfrom the bottom end surface 152 of the optional battery pack housing 144and abutting the lower bottom end surface 122 of the portableradiotelephone housing 104.

Although the portable radiotelephone 100 is illustrated and describedhereinbelow, it will be recognized that any one of a number portableelectronic devices, such as lap top computers, camcorders, pagers, twoway radios, personal digital assistants, and the like, could utilize thelatching mechanism 160 and the method of latching described hereinbelowfor attaching any accessory thereto, including a battery pack.

FIG. 2 illustrates a rear, left side, and top perspective view of theportable radiotelephone 100. The optional battery pack retaining device123 is further shown in FIG. 2. The optional battery pack retainingdevice 123 includes a raised area 200 integrally formed with the lowerrear surface 120 and located in proximity to the lower top end surface112. The raised area 200 includes an elliptical face surface 202extending outward from the lower rear surface 120 and a ramped portion204 sloping back downward from the elliptical face surface 202 to thelower rear surface 120. The elliptical face surface 202 includes a notch206 that faces in an upward direction but extends downward toward thelower bottom end surface 122. The notch 206 serves as a receptacle forthe latch 162 of the latching mechanism 160. By providing the raisedarea 200, space within the portable radiotelephone housing 104 isconserved. Aside from the raised area 200, the lower rear surface 120 isdevoid of any other latching receptacles that would detract from theappearance of the portable radiotelephone 100 when the optional batterypack 102 is not attached thereto.

Placing concerns about space savings aside, it will be recognized thatthe notch 206 could also be disposed in either the lower rear surface120 or the lower top end surface 112 to extend within the portableradiotelephone housing 104 and towards the lower bottom end surface 122.Placed as such, the notch 206 would be equally capable of receiving thelatch 162 of the latching mechanism 160 (see FIG. 1).

FIG. 2 also illustrates a set of flat contacts 208 disposed behind aseries of openings 210 in the lower rear surface 120 in proximity to thelower bottom end surface 122. The set of flat contacts 208 areelectrically connected to the transceiver circuit 700 (see FIG. 7)disposed within the portable radiotelephone housing 104. Upon attachmentof the optional battery pack 102, the portable radiotelephone 100 isable to operate via power supplied to the set of flat contacts 208 bythe optional battery pack 102. The set of flat contacts 208 are furtherdiscussed below in relation to FIG. 7.

Also shown in FIG. 2 is main battery 135 associated with upper housingportion 108. A latch member 212 at a distal end portion 214 of the mainbattery operatively mates with an associated latch member 216 of upperportion 108. Although outer surface 216 of main battery 135 forms aflush surface with upper rear surface 132, outer surface 216 of mainbattery 135 could extend above upper surface 132 to provide additionalroom for more or larger cells to provide greater capacity. The couplingof main battery 135 will be described in more detail in reference toFIGS. 10-14.

FIG. 3 illustrates a bottom plan view of the portable radiotelephone100. The optional battery pack retaining device 123 is further shown inFIG. 3. The optional battery pack retaining device 123 includes a rightreceptacle 300 and a left receptacle 302 formed in the lower bottom endsurface 122 in proximity to the lower right surface 126 and the lowerleft surface 124, respectively. The right and left receptacles 300, 302extend into the lower housing portion 106 towards the lower top endsurface 112 (see FIG. 7). By positioning the right and left receptacles300, 302 on the lower bottom end surface 122 the appearance of theportable radiotelephone 100 is minimally impacted when the optionalbattery pack 102 is not attached. The right and left receptacles 300,302 are of a diameter that is sized to permit insertion of a portion ofthe support 164 of the optional battery pack 102.

FIG. 3 also illustrates an external connector 304 disposed behind anopening 306 in the lower bottom end surface 122. The external connector304 is connected to the transceiver board 700 (see FIG. 7) and allowsthe user to attach the portable radiotelephone 100 to an external powersource, such as the battery of an automobile (not shown), for operatingthe portable radiotelephone 100 or charging the main battery pack 135.Such attachment can be accomplished by attaching a cigarette lighteradapter cable (not shown) between the external connector 304 and acigarette lighter plug (not shown) of the automobile. The externalconnector 304 may also be used to couple the portable radiotelephone 100to a hands free user interface (not shown) mounted in the automobile.The hands free user interface assists the user in many of the routineoperations of the portable radiotelephone 100.

FIG. 4 illustrates a front, right side, and top perspective view of theoptional battery pack 102. The latching mechanism 160 of the optionalbattery pack 102 is further shown in FIG. 4. The latch 162 of thelatching mechanism 160 includes a catch 400 that extends upward througha top opening 401 in the top end surface 150. The catch 400 includes areceptacle 402 adjacent to a hooked end 404. The hooked end 404 extendstoward the bottom end surface 152 and, in the preferred embodiment, issubstantially parallel to the front surface 146 of the optional batterypack housing 144. The hooked end 404 is sized to engage the notch 206 ofthe raised area 200 of the optional battery pack retaining device 123(see FIG. 2). To accommodate the raised area 200 of the portableradiotelephone 100, the optional battery pack housing 144 includes arecessed area 406 allowing edges 408 and 410 of the right and left sidesurfaces 154, 156, respectively, to perpendicularly abut the lower rearsurface 120 of the portable radiotelephone 100 when the optional batterypack 102 is attached thereto, as shown in FIG. 1.

The support 164 of the latching mechanism 160 includes a right foot 412and a left foot 414 extending planarly from the bottom end surface 152and the respective edges 408, 410 of the right and left side surfaces154, 156. The right and left feet 412, 414 are substantial mirror imagesof one another. The right and left feet 412, 414 include a right rampedtop surface 416 and a left ramped top surface 418, respectively. Theright and left ramped top surfaces 416, 418 slope downwards from therespective edges 408, 410 and are contoured to tightly abut the lowerbottom end surface 122 of the portable radiotelephone 100 which iscurved (see FIG. 2). The right and left feet 412, 414 are sized andoriented to allow access to, and prevent obstruction of, the externalconnector 304 (see FIG. 3) when the optional battery pack 102 isattached.

A cylindrical prong 420 extends upward from each of the right and leftramped top surfaces 416, 418. The cylindrical prong 420 extendsperpendicular to the bottom end surface 152 of the optional battery packhousing 144 and parallel to the front surface 146 of the optionalbattery pack housing 144. During attachment of the optional battery pack102 to the portable radiotelephone 100, the cylindrical prong 420 ofeach of the right and left ramped top surfaces 416, 418 inserts into theright and left receptacles 300, 302, respectively, as the right and leftramped top surfaces 416, 418 move into abutment with the lower bottomend surface 122 of the portable radiotelephone 100 (see FIGS. 2 and 3).The cylindrical prong 420 has a diameter that is sized slightly smallerthan the right and left receptacles 300, 302 to ensure a snug fittherein.

Putting concerns of obstructing the external connector 304 aside, itwill be recognized that the support 164 of the latching mechanism 160could comprise a single foot (not shown) extending planarly from thebottom end surface 152 to abut all or a portion of the lower bottom endsurface 122. The single foot could include either a single oblongcylindrical prong or multiple cylindrical prongs, each similar tocylindrical prong 420, that insert into a corresponding single oblongreceptacle or corresponding multiple receptacles, each similar to theright and left receptacles 300, 302 disposed in the portableradiotelephone 100.

FIG. 4 further illustrates a set of projecting contacts 422 extendingfrom the front surface 146 of the optional battery pack housing 144. Theset of projecting contacts 422, as shown, consists of a positive contact424, a thermistor sense contact 426, a data contact 428, and a negativeor ground contact 430. Positive and negative polarities of a pluralityof electrochemical cells 636 (see FIG. 6) disposed within the optionalbattery pack housing 144 are coupled to the respective positive andnegative contacts 424, 430. A thermistor (not shown) disposed within theoptional battery pack housing 144 is coupled between the negativepolarity and the thermistor sense contact 426 for providing a resistancethat may be used by a charger (not shown) to determine the temperatureof the plurality of electrochemical cells 636 while the optional batterypack 102 is being charged. A resistive network or microprocessor (notshown) indicating the type of the plurality of electrochemical cellsdisposed within the optional battery pack housing 144 may be coupled tothe data contact 428 to provide the identity of the plurality ofelectrochemical cells 636 to both the charger and the portableradiotelephone 100 for charging and discharging optimization. Uponattachment of the optional battery pack 102 to the portableradiotelephone 100, the contacts of the set of projecting contacts 422of the battery pack 102 mate with respective contacts of the set of flatcontacts 208 of the portable radiotelephone 100 (see FIG. 2).

FIG. 5 illustrates a front, right side, and top perspective view of thelatch 162 of the latching mechanism 160. The latch 162 may beprogressively stamped from beryllium copper alloy and heat treated, suchas Brush Alloy 25 manufactured and sold by Brush Wellman Inc. Aside fromthe catch 400, the latch 162 includes an arm 502 and a crossbar 510. Thearm 502 extends vertically between a midpoint of the crossbar 510 andthe catch 400. The arm 502 includes a front surface 503 and a rearsurface 504 with a right edge 505 and a left edge 506 extendingtherebetween. A first guide flange 507 and a second guide flange 508extend outward and orthogonally rearward from opposing locations on theright and left edges 505, 506, respectively.

The crossbar 510 extends horizontally with respect to the arm 502. Themidpoint of the crossbar 510 is defined by a central hub 512 thatextends orthogonally rearward from an end of the arm 502 opposite thecatch 400. The central hub 512 has a width that is equal to that of thearm 502. The central hub 512 includes a top surface 515 and a bottomsurface 517 interconnected by a curved edge 519. A first finger 516extends coplanarly rightward from the curved edge 519. A second finger520, which is substantially a mirrored image of the first finger 516,extends coplanarly leftward from the curved edge 519 directly oppositeto the first finger 516. The first and second fingers 516, 520 are of awidth that is less than that of the central hub 512.

The crossbar 510 is dimensioned to allow the first and second fingers516, 520 to flex in a plane perpendicular to the central hub 512. Whenends of the crossbar 510 are supported or anchored, a perpendicularforce applied to either the top or bottom surfaces 515, 517 of thecentral hub 512 causes the crossbar 510 to bow and the central hub 512to deflect. Removal of the perpendicular force causes the crossbar 510to straighten. The crossbar 510 operates as a spring that is biasedtowards the straightened position. Therefore, when the central hub 512is deflected above the ends of the crossbar 510, the crossbar 510 exertsa downward force. This downward force is translated to the hooked end404 of the catch 400 via the arm 502 and enables sufficient latching ofthe optional battery pack 102 to the portable radiotelephone 100.

To determine the downward force necessary to maintain the optionalbattery pack 102 in attachment to the portable radiotelephone 100, thefollowing factors were considered: the weight of the optional batterypack 102; the spring force of the set of projecting contacts 422; theamount of surface area of the support 164; the length and quantity ofthe cylindrical prongs 420 of the support 164; the orientation of thecylindrical prongs 420 and the hooked end 404; and the depth andorientation of the notch 206 and the right and left receptacles 300, 302of the optional battery pack retaining device 123. In view of thefactors, a force of approximately 22 N was determined to be sufficient.

To calculate the dimensions of the crossbar 510 necessary to exertapproximately 22 N of force while the optional battery pack 102 isattached to the portable radiotelephone 100, the crossbar 510 wasmodeled as a leaf spring. The leaf spring is governed by the followingknown equation (derived from Machinery's Handbook by Erik Oberg and F.D. Jones, 1970, Industrial Press Inc.): ##EQU1## where L is the lengthof the leaf spring,

E is the modulus of elasticity of the leaf spring,

b is the width of the leaf spring, and

t is the thickness of the leaf spring,

∂ is the defection at the center of the leaf spring,

and

F is force.

For clarity, the dimensions of the leaf spring recited hereinbelow arespecified in FIG. 5.

In solving the equation, the following assumptions were made:

1. The length L of the leaf spring is reduced by width w1 of the centralhub 512 (6 mm) which remains rigid during the bowing of the crossbar 510and by lengths l2 and l3 of the crossbar 510 (2 mm and 2 mm) which aresupported or anchored during the bowing of the crossbar 510.

2. The modulus of elasticity (E) is approximately 1.32E5 N/mm² forberyllium-copper alloy having a thickness (t) of 0.5 mm.

3. The width of the leaf spring (b) is 2.75 mm.

4. The deflection at the center of the leaf spring (∂) is 3 mm when thelatch 162 is extended to the engaged position 648 (see FIG. 6).

5. The force (F) is 22 N.

These assumptions result in the following: ##EQU2##

FIG. 6 illustrates a front elevational view of the optional battery pack102 having a front surface 146 removed and multiple positions of thelatch 162. The optional battery pack housing 144 is molded to engage thelatch 162. The optional battery pack housing 144 includes a first anchor600 disposed on a right side inner surface 601 thereof. The first anchor600 is formed by a right triangular front ledge 602 and a righttriangular rear ledge 604 offset and interconnected by a right wall 606.A second anchor 608, which is substantially a mirrored image of thefirst anchor 600, is disposed on a left side inner surface 610 directlyopposite the first anchor 600. The second anchor 608 is formed by a lefttriangular front ledge 612 and a left triangular rear ledge 614 offsetand interconnected by a left wall 616.

The optional battery pack housing 144 includes a track 618 that extendsdownward from the top opening 401 in the top end surface 150 in adirection that is coplanar with the front surface 146 (when attached).The track 618 further extends perpendicularly rearward with respect tothe front surface 146 to a rear inner surface 619 of the rear surface148. Right and left parallel edges of the track 618 are defined by aright rail 620 and a left rail 626, respectively. The right and leftrails 620, 626 extend orthogonally frontward from the track 618. A rightshelf 622 extends between an upper portion of the right rail 620 and theright side inner surface 601. A left shelf 628, opposite the right shelf622, extends between an upper portion of the left rail 626 and the leftside inner surface 610. A right trough 624 and a left trough 630adjoining and extending along the right and left rails 620 and 626,respectively, are disposed in the track 618. The right and left troughs624, 630 extend between the top opening 401 and a stop 631, which isdisposed on an end of the track 618 opposite the top opening 401. Thestop 631, which is flush with the track 618, extends perpendicularlyrearward therefrom to the rear inner surface 619.

The optional battery pack 102 includes a switch 632 for preventing theoptional battery pack 102 from providing power when it is not attachedto the portable radiotelephone 100. The switch 632 is positioned at apredetermined distance beneath the stop 631. The switch 632 is held in aU-shaped channel 634 that extends frontward from the rear inner surface619. The switch 632 is electrically coupled between a first wire 638carrying a positive polarity of the plurality of electrochemical cells636 and a second wire 640 coupled to the positive contact 424 of the setof projecting contacts 422. The switch 632 includes a button 642extending from a top surface thereof. When the button 642 is depressed,the switch 632 is placed in an opened state wherein the first wire 638and the second wire 640 are electrically disconnected such that thepositive polarity of a plurality of electrochemical cells 636 is notdelivered to the positive contact 424. When the button 642 is notdepressed, the switch 632 is placed in a closed state wherein the firstwire 638 and the second wire 640 are electrically connected such thatthe positive polarity of a plurality of electrochemical cells 636 isdelivered to the positive contact 424.

Although the switch 632 is disclosed as an electromechanical switch, itwill be recognized that switching could be accomplished by amicroprocessor circuit (not shown) disposed within the optional batterypack 102. The microprocessor circuit detects attachment of the optionalbattery pack 102 to the portable radiotelephone 100 via, for example, anoptical sensor (not shown) or a magnetic reedswitch (not shown) coupledthereto and connects or disconnects the plurality of electrochemicalcells 636 accordingly.

The latch 162 is assembled into the optional battery pack housing 144 asfollows. The latch 162 is first positioned such that the arm 502 isgenerally juxtaposed with the track 618 between the right and left rails620, 626. Also, the ends of the crossbar 510 rest on the right and lefttriangular rear ledges 604, 614 and curved edge 519 of the central hub512 contacts the side of the button 642 of the switch 632. The latch 162is then rotated about the crossbar 510 causing the catch 400 to movefrontward (out of the page) while a force in a direction of arrow 644 isapplied on the central hub 512 until the first and second guide flanges507, 508 clear the stop 631 and curved edge 519 clears the button 642.During the rotation and application of the force, the crossbar 510 bowsabout the central hub 512 causing the ends thereof to tightly abut theright and left walls 606, 616, respectively, and causing the central hub512 to be vertically deflected. Assembly of the latch 162 into theoptional battery pack housing 144 is completed when the bottom surface517 of the central hub 512 depresses the button 642 of the switch 632and the first and second guide flanges 507, 508 inserts into the rightand left troughs 624, 630, respectively, and rest against a top surfaceof the stop 631.

The latch 162 is further maintained in assemblage by the front surface146 (see FIG. 4) of the optional battery pack housing 144. The optionalbattery pack housing 144 includes mounts 652 extending from the innerright side surface 601, the inner left side surface 610, and an innerbottom surface 654 of the bottom end surface 152. The mounts 652 matewith snaps (not shown) positioned about a periphery of an underside ofthe front surface 146. To assemble the front surface 146 to the optionalbattery pack housing 144, the front surface 146 is positioned such thata central groove (not shown) formed on the underside of the frontsurface 146 beneath the recessed area 406 engages the right and leftrails 620, 626. The front surface 146 is then angled slightly and slidsuch that a right flap and a left flap (not shown), which are formed toextend upward from the underside of the recessed area 406 on either sideof the groove, are drawn under the right and left shelves 622, 628,respectively, of the optional battery pack housing 144. The frontsurface 146 is then angled back rearwardly until the snaps on theunderside of the front surface 146 mate with the mounts 652. Once thefront surface 146 is attached, the arm 502 is maintained injuxtaposition with the track 618 and the first and second guide flanges507, 508 are maintained in the right and left troughs 624, 630,respectively. The latch 162 is restricted to movement in a plane that isparallel to the front surface 146 and perpendicular to the top endsurface 150.

Once assembled, the latch 162 resides in a rest position 646 that isdefined by a slight deflection of the central hub 512 above the ends ofthe crossbar 510 as shown in FIG. 6. In the rest position 646, theoptional battery pack 102 is unattached from the portable radiotelephone100. The first and second guide flanges 507, 508 abut the top surface ofthe stop 631. The button 642 of the switch 632 is depressed by thebottom surface 517 of the central hub 512 disconnecting the plurality ofelectrochemical cells 636 from the set of projecting contacts 422. Bydisconnecting the plurality of electrochemical cells 636 when theoptional battery pack 102 is unattached, discharging and adverse heatingof the optional battery pack 102 is prevented should the set ofprojecting contacts 422 come into contact with a foreign conductiveobject while the optional battery pack 102 is being carried on the user.

When attaching the optional battery pack 102 to the portableradiotelephone 100, the latch 162 is first extended from the restposition 646 to an engaging/disengaging position 650 and then releasedto an engaged position 648, both of which are shown in dotted line inFIG. 6. The range of extension of the latch 162 is defined by deflectionof the central hub 512 between the rest position 646 and a bottomsurface of the stop 631. Any extension of the latch 162 from the restposition 646 causes the first and second guide flanges 507, 508 to moveupward in the right and left troughs 624, 630, respectively, away fromthe stop 631; the ends of the crossbar 510 to pivot about the right andleft walls 606, 616; and the central hub 512 to further deflect andrelease the button 642 of the switch 632. Once the button 642 isreleased as shown in dotted line in FIG. 6, the plurality ofelectrochemical cells 636 are connected to the set of projectingcontacts 422 and power may be provided therefrom.

The engaging/disengaging position 650 describes the position of thelatch 162 and the amount of deflection of the central hub 512 when theoptional battery pack 102 is being attached to, or detached from, theportable radiotelephone 100. In the engaging/disengaging position 650,the latch 162 is extended beyond the engaged position 648 to, amongother things, permit alignment of the cylindrical prong 420 of the rightand left feet 412, 414 of the support 164 of the optional battery pack102 beneath the respective right and left receptacles 300, 302 of theoptional battery pack retaining device 123 of the portableradiotelephone 100.

FIG. 7 illustrates a cross-sectional view of the portable radiotelephone100 and attached optional battery pack 102 taken along section lines1--1 of FIG. 1. The engaged position 648 describes the position of thelatch 162 and the amount of deflection of the central hub 512 of thecrossbar 510 when the optional battery pack 102 is attached to theportable radiotelephone 100. In the engaged position 648, the hooked end404 of the latch 162 engages the notch 206 of the optional battery packretaining device 123 with a force 701 (approximately 22 N), to maintainthe optional battery pack 102 in attachment with the portableradiotelephone 100. The force 701 imparted by the hooked end 404 on thenotch 206 and the surrounding elliptical face surface 202 effectivelypushes both the right and left receptacles 300, 302 (see FIG. 3) aroundthe cylindrical prongs 420 of the right and left feet 412, 414 of thesupport 164 (see FIG. 4) and the lower bottom end surface 122 of theportable radiotelephone 100 into snug abutment with the right and leftramped top surfaces 416, 418 of the right and left feet 412, 414 of thesupport 164.

When in the engaged position 648, the set of projecting contacts 422 ofthe optional battery pack 102 are in electrical contact with the set offlat contacts 208 of the portable radiotelephone 100. Each of the set ofprojecting contacts 422 are spring loaded to depress from a fullyextended position (see FIG. 4) upon contact with the set of flatcontacts 208 so as to minimize the force required to maintain theoptional battery pack 102 in attachment with the portable radiotelephone100. The operation of all of the contacts of the set of projectingcontacts 422 is exemplified in FIG. 7, which shows the thermistor sensecontact 426 in a depressed position. A spring 702 is disposed beneaththe thermistor sense contact 426 to permit easy depression thereof uponcontact with a corresponding contact of the set of flat contacts 208.The spring 702 biases the thermistor sense contact 426 towards the fullyextended position such that when depressed, the thermistor sense contact426 is still maintained in electrical contact with the correspondingcontact of the set of flat contacts 208.

Once attached, the plurality of electrochemical cells 636 of theoptional battery pack 102 preempt the main battery pack 135 and theoptional battery pack 102 powers the portable radiotelephone 100. Thisis accomplished by a fast switch (not shown) that is coupled between themain and optional battery packs 135, 102 and the transceiver board 700and is controlled by the transceiver board 700. Therefore, when both themain and optional battery packs 135, 102 are coupled to the transceiverboard 700, the portable radiotelephone 100 operates from the optionalbattery pack 102. Prior to complete discharge and/or removal of theoptional battery pack 102, the fast switch automatically switches fromthe optional battery pack 102 to the main battery 135 withoutinterrupting the operation of the portable radiotelephone 100. Onceremoved, the optional battery pack 102 may be recharged while theportable radiotelephone 100 operates via power provided by the mainbattery pack 135. Once recharged, the optional battery pack 102 can bereattached and switched to power the portable radiotelephone 100. Whileattached to the portable radiotelephone 100, the main and optionalbattery packs 135, 102 may be charged by attaching a charger to theexternal connector 304 of the portable radiotelephone 100. When chargedin this manner, the transceiver board 700 charges the main battery pack135 to completion prior to switching and charging the optional batterypack 102. Main battery pack 135 may also be removed by applying pressureto a lever arm 704 which is coupled by a fulcrum 706 to a fixed portion708 of the main battery. The battery is tilted downward as shown andremoved.

FIG. 8 illustrates a flow chart of a method of latching the optionalbattery pack 102 to the portable radiotelephone 100. Initially, thehooked end 404 of the latch 162 of the latching mechanism 160 (see FIG.3) is inserted into the notch 206 of the optional battery pack retainingdevice 123 (see FIG. 2), at step 800.

The optional battery pack 102 is then pulled downward at an angle untilthe cylindrical prongs 420 of the right and left feet 412, 414 of thesupport 164 of the latching mechanism 160 (see FIG. 4) clear the lowerbottom end surface 122 of the portable radiotelephone 100 (see FIG. 2),at step 802. As the optional battery pack 102 is pulled downward, thelatch 162 is extended from the rest position 646 releasing the button642 of the switch 632 (see FIG. 6). Once released, the plurality ofelectrochemical cells 636 are coupled to the set of projecting contacts422. The optional battery pack 102 is pulled downward until the latch162 is in the engaging/disengaging position 650.

At step 804, the optional battery pack 102 is maintained in theengaging/disengaging position and rotated about the hooked end 404 andangled back until the front surface 146 of the optional battery pack 102(FIG. 4) is in juxtaposition with the rear surface 120 of the portableradiotelephone 100 (FIG. 2). Once juxtaposed, the set of projectingcontacts 422 of the optional battery pack 102 depress and electricallycontact a lower portion of the set of flat contacts 208 of the portableradiotelephone 100. With the switch 632 already released, the pluralityof electrochemical cells 636 provide power to the portableradiotelephone 100 via the electrical connection of the set ofprojecting contacts 422 and the set of flat contacts 208. Thecylindrical prongs 420 of the latching mechanism 160 are aligneddirectly beneath the corresponding right and left receptacles 300, 302(see FIG. 3) of the optional battery pack retaining device 123 of theportable radiotelephone 100.

Attachment of the optional battery pack 102 to the portableradiotelephone 100 becomes complete with the execution of step 806,which denotes releasal of the optional battery pack 102 so as to allowthe optional battery pack 102 to move upward and cause the cylindricalprongs 420 to insert into the right and left receptacles 300, 302 andthe right and left ramped top surfaces 416, 418 (see FIG. 4) to abut thelower bottom end surface 122 of the portable radiotelephone 100. Withreleasal, the set of projecting contacts 422 remain depressed and inelectrical contact with the set of flat contacts 208 as they move toreside in an upper portion of the set of flat contacts 208 (see FIG. 7).Once attached, the latch 162 resides in the engaged position 648 (seeFIGS. 6 and 7).

Detachment of the optional battery pack 102 from the portableradiotelephone 100 is illustrated by substantially reversing the orderof the aforementioned steps 800-806. To accomplish detachment, theoptional battery pack 102 is first pulled downward until the cylindricalprongs 420 are completely removed from the right and left receptacles300, 302 and the latch 162 moves from the engaged position 648 to theengaging/disengaging position 650; the optional battery pack 102, whilemaintained in the engaging/disengaging position 650, is next rotatedabout the hooked end 404 so as to remove the front surface 146 from itsjuxtaposition with the rear surface 120 of the portable radiotelephone100 and remove the set of projecting contacts 422 from electricalcontact with the set of flat contacts 208; and, finally, the optionalbattery pack 102 is released thereby permitting removal of the hookedend 404 from the notch 206 and retraction of the latch 162 from theengaging/disengaging position 650 to the rest position 646. Onceretracted to the rest position 646, the button 642 of the switch 632 isonce again depressed thereby causing the plurality of electrochemicalcells 636 to become disconnected from the set of projecting contacts422.

FIG. 9 illustrates the portable radiotelephone 100 having the optionalbattery pack 102 attached thereto and an associated accessory. Asidefrom latching the optional battery pack 102 to the portableradiotelephone 100, the latch 162 includes the receptacle 402 (see FIG.4) to allow attachment of the portable radiotelephone 100 into anaccessory, such as a hang-up cup, while the optional battery pack 102 isattached to the portable radiotelephone 100. In FIG. 9, the portableradiotelephone 100 with the optional battery pack 102 attached theretois positioned above a hang-up cup 900. The hang-up cup 900 includes afront surface 902 having a top side 904, a right side 906, a bottom side908, and a left side 910 extending rearward therefrom. The front surface902 includes a recess 912 that is sized in accordance with the optionalbattery pack housing 144. The recess 912 includes a bottom surface 913defining the depth thereof. A latch member 914 extends into the recess912 from a top sidewall 918 of the recess 912 that extends opposite thetop side 904 between the front surface 902 and the recessed surface 913.A button 916 that is depressible is biased to extend from a rightopening 918 in the right side 906 of the hang-up cup 900. Upondepression of the button 916 into the right opening 920, the latchmember 914 retracts into the top sidewall 918 from a latching positionshown in FIG. 9. The hang-up cup 900 is typically mounted within thepassenger compartment of a vehicle (not shown) and in close proximity tothe operator of the vehicle to temporarily hold the portableradiotelephone 100 while it is not being used by the operator.

The portable radiotelephone 100 with the optional battery pack 102attached thereto is attached to the hang-up cup 900 by juxtaposing therear surface 148 of the optional battery pack housing 144 and therecessed surface 913 of the hang-up cup 900 while depressing the button916 and retracting the latch member 914. When the portableradiotelephone 100 with the optional battery pack 102 attached theretois positioned in the recess 912, the button 916 is released causing thelatch member 914 to engage the receptacle 402 of the latch 162 astelegraphed by dotted line 922. The portable radiotelephone 100 with theoptional battery pack 102 attached thereto remains securely attached tothe hang-up cup 900 until the user depresses the button 916 to retractthe latch member 914 and lift the portable radiotelephone 100 with theoptional battery pack 102 attached thereto away from the recess 912.

Turning now to FIGS. 10-14, the coupling of main battery pack 135 to theportable electronic device is shown. As shown in FIG. 10, the portableelectronic device is in a closed position with main battery pack 135detached. A recessed region 1002 for receiving the main battery packcomprises a first side wall 1004 and a second side wall 1006, and a rearwall 1008. A flange 1010 extends outward from the rear wall and over therecessed area. A second recessed area 1012 of upper rear surface 132provides a flat surface for supporting an associated flange 1013 of mainbattery 135. A mating latch member 1013 comprises a recessed area 1014having shoulders 1015 and 1016 adapted to receive latch member 212 toremovably attach the main battery to the portable electronic device.When main battery 135 is inserted into recess 1002, a protrusion 1017 ata distal end 1018 of main battery 135 is adapted to be inserted belowflange 1010.

As shown in FIG. 11, the inside and front walls of a recessed region forreceiving the main battery pack includes contacts 1104-1110 which areadapted to mate with contacts 1202-1208 on the front surface of mainbattery pack 135 (FIG. 12). When main battery pack 135 is inserted intorecess 1002, shoulders 1210 and 1212 are adapted to be inserted undershoulders 1015 and 1016. Edges 1020 and 1022 form a flush surface withside walls 1004 and 1006 respectively.

In summary, a latching mechanism disposed on an optional accessory, suchas an optional battery pack, for attaching the optional battery pack toa portable electronic device, such as a portable radiotelephone,includes a support and a moveable latch that mate with first and secondportions of a retaining device disposed on opposite ends of the portableradiotelephone. Because the retaining device is for an optional batterypack to supplement a main battery attached elsewhere on the portableradiotelephone, the retaining device should only minimally affect theappearance when the optional battery pack is not attached. The supportincludes a foot having a prong that is disposed on a first end of theoptional battery pack and faces a hooked end of the moveable latchdisposed on a second end of the optional battery pack. The moveablelatch includes a spring disposed within the optional battery pack andcoupled to the hooked end such that when the moveable latch is extended,the hooked end exerts a force on the first portion of the retainingdevice that draws the support into snug abutment with the second portionof the retaining device. The force, which is in a plane parallel to afront surface of the optional battery pack that extends between the endsthereof, maintains the optional battery pack in attachment with theportable radiotelephone allowing the optional battery pack to deliverpower to the portable radiotelephone.

We claim:
 1. A portable foldable radiotelephone comprising:a firsthousing portion having first and second ends spaced by a first length; atransceiver positioned in said first housing portion; a second housingportion having first and second ends and first and second sides, saidfirst and second ends of said second housing portion spaced by a secondlength substantially equal to the first length, said first and secondsides of said second housing portion extending between said first andsecond ends of said second housing portion; a hinge positioned at saidsecond end of said first housing portion and at said second end of saidsecond housing portion; an inner wall positioned in said second housingportion to extend between said first and second sides of said secondhousing portion; a speaker enclosure formed in said second housingportion, said speaker enclosure bounded by said first end of said secondhousing portion, said inner wall, said first and second sides of saidsecond housing portion, a first surface of said second housing portionand a second surface of said second housing portion; a speakerpositioned in said speaker enclosure; a recess formed in said secondhousing portion, said recess bounded by said first surface of saidsecond housing portion, said first and second sides of said secondhousing portion, said inner wall and said second end of said secondhousing portion, said recess for receipt of a battery pack; a matinglatch member associated with said recess; a first plurality of batterycontacts associated with said recess; and a battery pack adapted to beremovably received in said recess, said battery pack having a latchmember and a second plurality of battery contacts, said latch member toengage said mating latch member, and said second plurality of batterycontacts to engage said first plurality of battery contacts.
 2. Aportable foldable radiotelephone according to claim 1 whereinsaid matinglatch member is formed on said inner wall, and said latch member iscarried on an end of said battery pack.
 3. A portable foldableradiotelephone according to claim 2 whereinsaid first plurality ofbattery contacts are carried in respective openings of said inner wall,and said second plurality of battery contacts are carried on said end ofsaid battery pack.
 4. A portable foldable radiotelephone according toclaim 3 whereinsaid mating latch member is located at a center of saidinner wall equidistant from said first and second sides of said secondhousing portion, a first one of said first plurality of battery contactsis positioned between the center of said inner wall and said first sideof said second housing portion, and a second one of said first pluralityof battery contacts is positioned between the center of said inner walland said second side of said second housing portion, said first andsecond ones of said first plurality of battery contacts equidistant fromthe center.
 5. A portable foldable radiotelephone according to claim 1whereinsaid first plurality of battery contacts are carried inrespective openings of said inner wall, and said second plurality ofbattery contacts are carried on an end of said battery pack.
 6. Aportable foldable radiotelephone according to claim 5 whereina first oneof said first plurality of battery contacts is positioned between acenter of said inner wall and said first side of said second housingportion, and a second one of said first plurality of battery contacts ispositioned between the center of said inner wall and said second side ofsaid second housing portion, said first and second ones of said firstplurality of battery contacts equidistant from the center.
 7. A portablefoldable radiotelephone comprising:a first housing portion having firstand second ends spaced by a first length; a transceiver positioned insaid first housing portion; a second housing portion having first andsecond ends and first and second sides, said first and second ends ofsaid second housing portion spaced by a second length substantiallyequal to the first length, said first and second sides of said secondhousing portion extending between said first and second ends of saidsecond housing portion; a hinge positioned at said second end of saidfirst housing portion and at said second end of said second housingportion; an inner wall positioned in said second housing portion toextend between said first and second sides of said second housingportion; a speaker positioned in said second housing portion betweensaid first end of said second housing portion and said inner wall andbetween said first and second sides of said second housing portion; arecess positioned in said second housing portion between said first andsecond sides of said second housing portion and between said inner walland said second end of said second housing portion, said recess forreceipt of a battery pack; a mating latch member formed on said innerwall, said mating latch member comprising a recessed area; a firstplurality of battery contacts associated with said recess; and a batterypack adapted to be removably received in said recess, said battery packhaving a latch member and a second plurality of battery contacts, saidlatch member comprising a fixed portion, a lever arm, and a fulcrumjoining said fixed portion to said lever arm, said fixed portionattached to an end of said battery pack, said lever arm movable underapplied pressure in a direction towards said end of said battery pack,and said fulcrum biasing said lever arm in a direction away from saidend of said battery pack, and, when said battery pack is removablyreceived in said recess, said lever arm inserting into said recessedarea to engage said latch member and mating latch member and said secondplurality of battery contacts engaging said first plurality of batterycontacts.
 8. A portable foldable radiotelephone according to claim 7whereinsaid recessed area further comprises first and second shoulders,said first shoulder of said recessed area positioned to extend from oneside of said recessed area, said second shoulder of said recessed areapositioned to extend from another side of said recessed area oppositesaid one side of said recessed area, and said lever arm furthercomprises first and second shoulders, said first shoulder of said leverarm formed in one side of said lever arm, said second shoulder of saidlever arm formed in another side of said lever arm opposite said oneside of said lever arm, said first shoulder of said lever arm to insertunder said first shoulder of said recessed area when said battery packis removably received in said recess, and said second shoulder of saidlever arm to insert under said second shoulder of said recessed areawhen said battery pack is removably received in said recess.
 9. Aportable foldable radiotelephone according to claim 7 whereinsaid firstplurality of battery contacts are carried in respective openings of saidinner wall, and said second plurality of battery contacts are carried onsaid end of said battery pack.
 10. A portable foldable radiotelephoneaccording to claim 9 whereinsaid mating latch member is located at acenter of said inner wall equidistant from said first and second sidesof said second housing portion, a first one of said first plurality ofbattery contacts is positioned between the center of said inner wall andsaid first side of said second housing portion, and a second one of saidfirst plurality of battery contacts is positioned between the center ofsaid inner wall and said second side of said second housing portion,said first and second ones of said first plurality of battery contactsequidistant from the center.
 11. A portable foldable radiotelephonecomprising:a first housing portion having first and second ends spacedby a first length; a transceiver positioned in said first housingportion; a second housing portion having first and second ends, firstand second sides, and first and second surfaces, said first and secondends of said second housing portion spaced by a second lengthsubstantially equal to the first length, said first and second sides ofsaid second housing portion extending between said first and second endsof said second housing portion, said first surface of said secondhousing portion extending from said first end of said second housingportion and between said first and second sides of said second housingportion, and said second surface extending between said first and secondends of said second housing portion and between said first and secondsides of said second housing portion; a hinge positioned at said secondend of said first housing portion and at said second end of said secondhousing portion; an inner wall extending between said first and secondsides of said second housing portion and between said first and secondsurfaces of said second housing portion; a speaker enclosure formed insaid second housing portion, said speaker enclosure bounded by saidfirst end of said second housing portion, said inner wall, said firstand second sides of said second housing portion, said first surface ofsaid second housing portion and said second surface of said secondhousing portion; a speaker positioned in said speaker enclosure; arecess formed in said second housing portion, said recess bounded bysaid first surface of said second housing portion, said first and secondsides of said second housing portion, said inner wall and said secondend of said second housing portion, said recess for receipt of a batterypack; a mating latch member formed on said inner wall to face saidrecess, said mating latch member comprising a recessed area having firstand second shoulders extending therefrom; a first plurality of batterycontacts carried in respective openings of said inner wall and facingsaid recess, a first one of said first plurality of battery contactspositioned between said recessed area of said mating latch member andsaid first side of said second housing portion, a second one of saidfirst plurality of battery contacts positioned between said recessedarea of said mating latch member and said second side of said secondhousing portion; and a battery pack adapted to be removably received insaid recess, said battery pack comprising first and second ends, firstand second surfaces, first and second sides extending between said firstand second ends of said battery pack and spaced apart by said first andsecond surfaces of said battery pack, a second plurality of batterycontacts carried on said first end of said battery pack, and a latchmember carried on said first end of said battery pack, said latch membercomprising a movable lever arm having first and second shoulders formedin sides thereof, and wherein, upon reception of said battery pack insaid recess, said first end of said battery pack juxtaposes said innerwall, said first and second shoulders of said lever arm insert underrespective ones of said first and second shoulders of said recessed areato thereby mate said latch member and mating latch member, said firstplurality of battery contacts mate with said second plurality of batterycontacts, said first surface of said battery pack joins flush said firstsurface of said second housing portion to form a continuous surface, atleast a portion of said first side of said battery pack joins flush saidfirst side of said second housing portion to form a continuous surface,and at least a portion of said second side of said battery pack joinsflush said second side of said second housing portion to form acontinuous surface.